"E heluhelu ʻoe i ka hapahā i hala ka hola ʻeono."

[DABurnside]

My aha! moment: Hapa means part of or fragment. Hā hearkens back to ʻehā (four), therefore, hapahā is a fourth part (not 15, but rather a quarter). Hola is how Hawaiians pronounce "hour." Hapalua is (hapa+ʻelua) two parts, or half (not 30, but half of the hour).

[jdmcowan]

Nice realization on hapahā and hapalua. Thanks for sharing.

[rabelon]

Yes. I see this as borrowed English for half. Hapa = half. Hapaha = Half of Half, which is a quarter.